This old radio sat for years...let's clean it up and replace the capacitors!
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- Опубліковано 14 гру 2022
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This is a Zenith B835E AM/FM tuner. It sat in my friend's grandparents' basement for quite a long time before we came across it this year. In this video I replace all of the capacitors, clean the switches, and put it back together!
Here's more info on this model: luxuryradios.com/en/zenith-b8...
Also: www.radiomuseum.org/r/zenith_... - Наука та технологія
Manufactured in 1956 in Chicago, Illinois. It's all hand wired and is one of the most reliable radios Zenith produced. Note that it has the Civil Defense triangular markings at 65 and 120 on the AM dial. All manufacturers between 1954 and 1963 were required to put them on, as those were where you had to tune for emergency broadcasts during the cold war.
For its age, that radio was in pretty decent shape!
I have the same radio. Picked it up from a thrift store not working. Open it up and the first thing I saw was the bumblebee next to the selenium rectifier had exploded with conductive foil all over the inside of the chassis. Needless to say, that cap was replaced along with the selenium rectifier.
Nice little radio, very stylish. Good design last the test of time.
When Mr. Carlson replaces a power cord he uses a polarized plug and makes sure that the chassis get the neutral side so as to prevent a shock hazard.
Changes the switch from the chassis side to the line side too. The line voltage travels through the filaments to the chassis when the power switch is open otherwise.
This was my concern on this rebuild.. especially after watching M. Carlson as much as I have and his concern for safe devices.
Ditto, and as others have noted, replace the selenium rectifier with a diode and dropping resistor. Someone also noted that there’s a cap across the line cord. If that’s case replace it with a safety cap.
@@leeball9083 Sometimes the across the line cap is on the line side of the power switch, so there is power across it even though the power switch is off! These can overheat an explode within minutes, or seconds, of simply plugging it in the wall.
I just replaced such a cap on an old Eico 315 tube signal generator. 400v paper waxie @ .01mfd, was leaking dc at 50 volts and would have overheated and popped. Replaced with Vishay axial XY safety cap, .01mfd 250vac.
You are my new favorite UA-cam channel!
Cool to see you reviving some older electronics… nice job, and also preserving bits of our “Made in America” heritage! Thanks!
A quick Google search says the Zenith B835R model was produced in Illinois in 1956. My 2-cents of info. Thanks for your video, as always.
Thought I would add my 2 cents in areas not covered in the other comments. I don't recommend turning on an old tube radio before addressing the old capacitor problems. Bringing the set up with the variac and series incandescent bulb is an excellent idea though. I bring up an old set by slowly charging up the electrolytic caps through a 1 meg resistor using an external power supply over several hours. I charge the cap to 10% more than its rated voltage. If it successfully charges, I then power up the radio with all the filaments. Just monitor the grid 1 (control grid) voltage on the audio ouput tube. It should be zero volts. If you have a positive voltage, turn off power, as the positive voltage causes excess plate current which can take out the audio output tube, audio output transformer, speaker field coil, rectifier tube, and power transformer. As a bare minimum, replace the audio output tube grid 1 (control grid) coupling cap.
I estimate your radio was manufactured in the mid 1950's.
Any capacitor connected across the power line or from power line to chassis should be a Safety Y-class type. These capacitors are designed to open in the event of a capacitor short to prevent the capacitor from catching on fire. Also, most of these radios did not have a line fuse. I like to use a flame proof 10 ohm, 2 watt resistor for this purpose. It addition to acting like a fuse, it also adds some surge protection and lowers the AC input voltage a few volts to account for the lower voltage the line used when that radio was manufactured.
In addition to cleaning the controls, selector switches, and tuning capacitor grounds, I also recommend cleaning the tube sockets, which can prevent mysterious intermittent problems.
The old leaky paper capacitors will always check high in value when using a basic DVM, due to the crude test circuit used within the meter.
That radio uses electrostatic tweeters. These (like the paper capacitors) become leaky over time and can pull considersble B+ current, that is probably why they were disconnected.
Those selenium rectifiers develope higher series resistance over time so, replacement is recommended. Replace using a 1N4007 diode with a series 100 ohm (approximately), 2 to 5 watt resistor. This resistor value should be varied to produce about 120 Vdc on the audio output tube plate.
I only use hard epoxy dipped plastic film capacitors to replace the paper capacitors. The type you used are called "wrap & fill", which have a moisture migration problem. They also easily short out if bumped by a soldering iron. I sleeve the leads with Teflon sleeving, which lasts forever. In like manner, any chassis hookup wire, I replace with 22 AWG, sliver plated stranded Teflon insulated wire (which lasts forever and does not melt with soldering iron heat).
Thanks for restoring a piece of history .
Nicely produced video from start to finish. I felt as though we explored this hidden treasure together. Those classic products have a unique charm that doubles if working.
I've got three words... Mr Carlsons Lab. He's got tons of good material on restoring these old tube amps.
Just so you know - You left one old cap in the radio. Right in the center bottom on top of the output transformer. That one is a bumble bee and you will have to figure out the value as it uses color rings like a resistor does. Those bumble bee caps are even worse than the wax paper caps as they tend to take in moisture easier over the years as they don't have a wax coating. Those things like to short so make sure you get that one replaced asap. EDIT: well I see someone else already mentioned it.
if u can find a free schematic from Sam's Photofact for Rider you can see the value of that cap. There will be a photo of the radio and each cap, resistor, etc. will be numbered in the photo and tied to a table of values. I have this radio. it's one of the few of its time with a good size speaker, mine sounds incredible.
Orienting the indicator is not an FM alignment. An FM alignment involves adjusting the various IF cans to the proper frequencies.
What a cool radio and repair video! Between your work and cool demeanor, very entertaining!
I own a 1936 Silvertone that belonged to my grand parents. The internals are all original and it works pretty well. I also have a 1942 and 1947 Silvertone. I recently bought a mint, restored RCA Victor with an RCA jack. I hook up an Echo Dot at Christmas time and play Christmas music. I really love those old radios!
Deep Rich only a valve radio can deliver, remember to circulate Air behind them so they do not get too warm
Just remember, all those old tube radios MUST have their paper and electrolytic capacitors changed out. Yes, I know the radio appears to play okay but, those old capacitors will destroy the audio output and rectifiers tubes, the speaker field coil, and power and audio output transformers, with some of these parts no longer being available.
Nice info, just bought a Zenith am fm receiver circa 1959 that hums a bit much so will be retracing this vid and trying to improve it. thanks.
Hodor looks just like my long departed Blackie. I really miss that cat.
Everyone else has given you grief about the big bumble bee output cap. To that I'll add: DO NOT put BOTH hands into one of those radios while it is powered up! If the wrong cap was shorted, you could get a lethal shock. When you had a hand on each one of those controls, I was waiting for something like the guy on the Electro-Boom channel does, only he does it on purpose for laughs.
I was cringing from the very start of this repair. Not knowing the name waxes, told me he was on his first rodeo! The way he didn't protect the speaker also was telling. But grabbing a chassis with out an isolation transformer was nuts. Unless his Varriac was designed to shield him, but it looked basic. Someone suggested the bulb. Thank goodness. Well he got it done. His FM alignment made me laugh. I guess without a signal generator you make due. Glad he didn't get shocked. But it was a tense watch for me. Great tuner!
You should definitely change that bumble bee capacitor behind the rectifier. They tend to explode with age with a "pop". I would also replace that rectifier with a 1N4007 diode and a dropping resistor as when those old selenium rectifiers do go bad they tend to let out smoke that smells worse than burnt garlic and it's an odor with a long lasting presence in a home. That variable capacitor was for the broadcast AM band and the slugs are the FM tuner. That "alignment" was funny, lol. I've done a few similar radios like the Zenith K-725. These models and yours I believe were called "Consoltones" as they were a table radio that was supposed to have the same big sound as Zenith's big console radios. They almost always work despite how old they get which makes the old motto of "Zenith--The quality goes in before the name goes on" pretty accurate :) I would have personally passed this one by myself as I've never been a fan of the "Blonde cabinets" preferring the dark red/brownish knobs and a dark finish like walnut or mahogany, but that's just me.
Now, wish me luck as I'm going to attempt to restore an RCA Radiola 60 model from 1928 full of globe tubes, lol.
Zenith. The quality goes IN before the name goes ON!
Amazing. I was raised in the same (victorian era) house as my grandfather, and in our parlor we still have the old gigantic tube television and tubed radio/record player. Both have been in the house since my great grandparents purchased them in the 40s-50s, and haven't moved at all. Once my great grandmother passed away my grandfather gave it to my mom to restore. She has restored everything house-wise, but hasn't ever touched the television or record player. I would love to restore them for her for xmas next year. Anyways, great video man!
Glad no issues in the recap here, well done. Working on live chassis equipment can be fool hardy if precautions not taken for sure and the vacuum tubes are another level in difficulty. I'm sure you'll be learning lots on your journey, good luck. See ya next time..
I enjoy your videos, and as I want to enjoy them in the future, please use an isolation transformer when testing these kind of radios. It's also a good idea to not put both hands on the chasis at the same time.
David Tipton, Mr Carlson's Lab, Electronics Old and New by M Caldeira channels, are some of the best masters to learn about repariring old radios safely. Regards, G.
Wow, flashback, we had one just like that Zenith. Many memories listening to it. Might still have it in storage, too.
I have this nearly exact radio, Mines a 1961. Different knobs, nicer fabric cover. Bought mine in 1986 at a garage sale. Its in beautiful shape, and I use it every morning while getting ready for work, mine has required 0 repairs, and I'm sure it hasn't been redone at all. I also have my great uncle's 1954 Zenith am fm phonograph console he bought new.In fact, its playing Christmas music right now as I write, very nicely ! Sounds great, original speaker too. I inherited it in 1994. In the 28 years I've owned it, its never had any issues, play it couple hours a week, lots of record playing. I'm sure he never had it overhauled, and I've done nothing to it, except use it. I turn it on, it always works! One day last year I forgot to turn it off, and left the house around 9 am came home around 1130 pm and saw the little light at the bottom of the cabinet. I was like oh no!! Turned it up, it was playing just fine!! ZENITH was the Sony of its time, their slogan was ZENITH, THE QUALITY GOES IN, BEFORE THE NAME GOES ON.
Well done, that is such a cool looking radio as well! Merry 🎄 Christmas!
Slugs are to tune FM. Its called PTO for "permeability tuned oscillator". Very expensive
way to do it but VERY stable.
BTW I thought I heard some distortion & hum on AM. One of the tubes causes that.
Either a 12BA6 or 12BE6, Dont remember which.
LFOD !
I swear to god if YOU didn't make these videos the art would die! I know it would be dead for me without you!
I found that exact same 1958, blonde model Zenith in a bag of trash about a year ago. Still haven't touched it. It has two tweeters. It's thought to be a stellar performer.
I had a radio very similar to this one. It looked slightly different but it was an AM/FM zenith. It was from about 1955. Nice job on the recapping work.
I had an old Zenith radio like this back when I was a kid (late 70s early 80s) The cabnet was just stained a darker color and the tuning knob had a fine adjustment ring around it. My friends had newer stereos but none sounded as good. It had a very rich full sound. Great radio!
That's a very nice radio. I laughed cause the FM on it sounds better than the FM on my Emerson weather radio made about 10-15 yrs ago. Of course the Emerson was cheaply manufactured overseas so I can't really compare the two despite the age difference. Great video, thanks and Merry Christmas!
I imagine you're new to antique electronics. There's a "bumblebee" style cap front and center that should be replaced also....... other than that, you're gold.
You did a really nice job on this Zenith. This radio is an excellent design that was used for several generations of Zeniths. I hate to say it, but you missed one capacitor. It’s the black bumblebee by the speaker magnet. Going by memory, but it might be a .047 MFD? Can’t remember. Anyway, these capacitors are known for being problematic, for what that’s worth. There’s lots of information and advice on these radios on the antique radio forum.
Hah, I thought it was just a big resistor!
@@AHFixIt
Sure looks like one but that ain't no resistor.
@@westelaudio943 Given its age, it might well be more resistor than capacitor at this point! Regardless, they're not called bumble-bombs without reason. Best to yank and replace.
@@AHFixIt make sure the capacitors are properly polarized because the machine can print the black band on the wrong side of the capacitors.
@@AHFixIt yes the capacitors go bad they turn into resistors they where crap when they where new technology anyway compared to capacitors made these days.
What a great looking radio 👍
Those tweeters are quite unique! They are electrostatic tweeters, they are high impedance and run right off of the primary plate side of the output tube. Sometimes they can short, since they are actually a capacitor which one plate is the stator and the other a diaphragm which causes the air to move by high tension electrostatic force. My first thought was that someone unhooked the tweeters because of a short.
Zenith also used them in some of the large console stereos in an array of three per channel. Zenith was always trying to be the best and the use of electrostatic tweeters was probably more of a sales gimmick, rather that practical.
They probably copied them from the german radios made back then. I have a bunch of german radios with electrostatic tweeters and they do add a lovely sparkle to the high-end.
I've worked on a couple of these radios. Not terribly difficult. The selenium rectifier should definitely be replaced as well as the main filter caps. Those small caps are wax/paper and prone to failure. These are fine sounding radios when working properly.
He left the worst capacitor of the bunch inside it. That big bumble bee cap behind the rectifier. That would have been the first one I changed.
@@Rebel9668 I did notice that as well.
Amazing video!
Zenith essentially used the same FM circuit from 1948 all the way until the 60's. It was reliable, performed well, and Zenith even paid royalties to the Armstrong family (unlike Philco and RCA). These were some of the best Zenith FM sets. Don't forget the bumble bee across the line cap - they like to explode! Also, the selenium rectifier should be replaced with a diode and dropping resistor to get the right B+. When those fail, the smell is incredibly bad!
Yes I agree the Bumble Bee Cap needs replacing its the big black
(resistor looking) like one in the middle of the radio, glad I'm not the only one
too comment on this. Nice job.
Zenith made some nice stuff. You forgot one capacitor in the middle of the radio the color coded one (bumblebee) and when restoring these radio's it's usually good practice to replace the selenium rectifier for an diode and a dropper resistor to counteract for the voltage drop over the selenium rectifier.
Yip the Big Black (resistor) looking one is a capacitor for across the line voltage
they like to go bang !!!
That bumblebee cap may be the across the line cap and I see the colors on it that says it is a .047 mfd. That should be changed right away. The selenium rectifier may work for awhile but it will need to be replaced for long term use. I have the same radio but a different color.
ZENITH baby! fix it, fix it, fix it.
Whenever I work on these I cover the speaker paper. They are delicate, a magnet for pokers and not really replaceable.
The first time I seen a Bumblebee style cap, I thought it was some type of special resistor.
That radio was one of the earley Hi Fi radios that had the 3 speakers, so Hi Fi came out around 1954 - 1955 so this radio is around that vintage of time..😊
I turned my old Zenith tabletop into a Google home. I love it and use it every day. The super efficient speaker actually sounds way better then it should
There was one you forgot! The one in the center, which is the black one which is striped which is next to the transformer in the bottom center!
Have a early 60s normende. Never been recapped. Works great sounds even better.
As long as there's no Magic Smoke, you're good to go! Zenith, the smoke goes up while the name goes on - company logo 😄
Good stuff! You should check the voltages on the tubes too, especially the output tube(s). Make sure they are not running too hot and if they are, you may have to adjust the bias. If you really wanna learn more about tube gear, you really need to watch the great 'Uncle Doug' channel where he breaks everything down how tube circuits work and how to fix, repair.....
Priceless info taught in a way the mere mortal can understand too.
The third knob in the middle will be the more accurate extra fine tuning knob and the other tuning is just to get you near to the desired station
Be careful and use an isolation transformer-no power transformer in radio to isolate you from mains. Also suggest replacing that bumble bee on the output transformer
I’ve restored a million of these. Be careful that’s a hot chassis set. The plungers are the tuning slugs for FM.
I remember that back in the day and radio try to broadcast in am stereo I've never heard a am radio station in a long time
The center knob is the fine tuning adjustment.
Good job, there are a lot of things to learn with these, but the only way to learn is getting in there and doing it.
That black plastic cap with the colored stripes (bumble bee) is also a paper cap inside, and these tend to explode, if it is an across the line cap, when they short. Looks like the last band is blue, which I believe is 600 volts. I bought a bunch of Vishay brand XY rated safety caps from Mouser for across the line replacements. Not a bad idea to use an XY rated cap for the external antenna coupling cap as well. Looking forward to the Bogen, cheers!
Good job. It works.
But you need to restore the appearance, wash and clean the control knobs, fabric, body...
the back with the cover off could be used for album art.
I just hope those small high-voltage electrolytic capacitors will withstand the ripple current they'll experience if they're used in the power supply!! Sounds like some switch cleaner might also help...
Very nice work on that radio ,you may want to replace that bumble bee capciator,and the sellinium retifier,both have a high fail rate.you don't see that many radios with fm,in that era.its a good idea to unplug vintage radios when not in use.
FM radio was around since the early 1950's. It was not popular and carried some classical music stations. I bought a 1965 Corvette, and it had a AM-FM radio in it. I remember that by 1966, popular AM stations began moving to FM. Once stereo FM was developed, most popular AM stations started to carry programming not in the mainstream.
Valve radios were really good, Clean ALL the Dust and Dirt OUT check for obvious damage, one BIG speaker in the middle so should have GOOD sound quality!! The main enemy of such radios is HEAT 🔥having a small fan behind them to flow air around is a good idea low cost too, my guess the knob in the middle of the speaker, fine tuning.
Its the TONE knob.😊
You forgot a cap. The black Sprague that looks like a huge resistor across the speaker is actually a cap. They call it a bumblebee, and at it's age is very prone to failure. I think in it's position it is a crossover capacitor for the small speakers, so maybe it's.not critical, but it will definitely improve sound and reliability to change it out. I AM NOT criticizing your work, it's great, I just wanted to point this out. PS, if that cap still has a close value, you can save it for a guitar amp input, people love those things in that low voltage circuit for it's sound properties.
I have one EXACTLY like it same color.
The capacitors you call oilie capacitors are actually called wax capacitors there made of wax and have a paper label wrapped around it and if not replaced they can cause problems so good job fixing it
For safety you should have polarized the chord to keep the classy from being hot.
I had one just like that with the accompanying 45 record player
This is the blonde oak wood cabinet so it is a B835E. The R is for the mahogany cabinet version. There is no schematic
made for this model but the SAMS Photofact 485 -18 is very close. That covers the C835 model. Also you may find that
SAMS 325-17 for the Y832 model is also very close. They were all made in the same year of 1956.
Great Job my dude learned a lot from your channel and xraytonyb appreciate everything , Would love to send you my Sansui Au 717 to have redone i pay good 😃
Did you try adjusting the tone know after spraying it? Also did you check the tunes to see if they were weak? Nice radio.
The radio is a Zenith Super Symphonaire from 1957 it was available in either a blond or mahogany cabinet and originally retailed for $109.95
A couple of things I've worked on were old enough to have been this one's parents.
Nice job!
What you figured out at the 15:00 mark was clever
Is it just me or is that a heck of a lot of parts for that size of kit?
Just video record what you are doing, or take pic's. And you always know the way it was before you messed up. They are tweeter speakers. Nice radio. Hand crafted chassis.
Push the tubes in fully. Will save problems later on.
where do you get the caps from?
This reminds pup of frequency from the 90s arfff!!! ^^ 😋
Nice job. Just one minor comment, those bumblebee caps are paper and oil, so are just as unreliable as the wax caps. If there's no voltage across it, it will be fine. Some go nuts about selenium rectifiers and they are reputedly pretty stinky if they blow but if there is no corrosion they are reliable. Interesting set FM as well. The high capacitance readings are just due to leakage.
I hope you noted the foil ends on those new caps and got them in the right direction, or you'll introduce some hummin'.
A much better way to check electrolytic caps is with an ESR cap analyzer as a cap may read OK on your multi-meter cap function but be starting to dry out and will break down and leak (electrically ), they can be used in circuit. I like GME 236 but there are cheaper ones.
Beautiful job why didnt you blow the dirt and grime off the tube base and flush everything out so its clean. I would of pulled all the tubes flush the bases and contacts and flushed the base and components would of been spot less. The dirt will attract static electricity and cause static in the system down the road .
I would replace the black bumblebee capacitor. Did u check the resistors? I bet there's some out of tolerance resistors because I thought I heard some distortion. Doing an alignment requires a signal generator. You will notice some gain on the volume.
Can these be converted to a mono block amplifier?
I would highly highly suggest replacing that selenium rectifier with a modern diode. There are many accounts of those giving up with a big explosion. I take the selenium rectifier out of circuit, but many people just short a wire across it without any issues.
Also, you might consider rebuilding those IF transformer cans. SMD will almost certainly show up with any real usage. Manifests as crackling on AM and poor reception on FM. There are videos here how to do it, but you want to take the silver mica capacitors out, put the can back together (making sure none of the leads are shorted), and put the capacitor replacements under the chassis. The values are known, so you should be able to find them around or reach out to me.
Are you from western PA ?
Did you check for outside foil like the originals? Important for noise suppression. See Mr. Carlson's Lab for information on that.
5:15 The tuning cap does not tune the fm. What you see on top is the slug tuning of the fm part of the radio.
a zenith record player could be re-wired for stereo and one channel could be amplifier using the amplifier in that radio
3 things would have done differently 1, replaced the black beauty cap there known to short 2, added a Thermistor on the filament circuit and added a fuse
i have the the same radio 1956 ,,,
I have that same model. Thought it was from 1958.
You should use a isolation transformer when working on AC DC radios.Because the chassis is Hot with 120 volts on it.
You bet I will subscribe! You have a real head on your shoulders, quite unlike many young druggies today. I shouldn't say all kids are like that but that is all you see on the news. I like the methodical way you worked though these old radios. I too had a old Zenith that had like five different bands on it. It went away when I moved to alaska. It sat in a large cherry wood cabinet and had the antenna under it that you turned for the best reception ... I kind of miss it but at 73, you kind of miss a lot of things
You may have a borderline tube in that radio
Do the axial caps have polarity? I replaced some in my KLH 17s and the new ones (daytons) aren’t labelled.
What kind of cap are they? If they are film caps, theoretically no. But you would want the outer foil closer to ground for better shielding.
Oh those are speakers... Nevermind then, speakers are low impedance so shielding doesn't really matter.
Don't use polarized electrolytics in speakers though.
When I watch your videos it's like watching me show a kid how to play Sim City 2000 except FAR FAR FAR MORE important and far less ADHD!!!
A simple but classy quality look to this unit! I wish you would clean this stuff up all the way before showing them at the end all grubby.
you need to test tubes and check resistors
That one sounds great.....h...g..725
Don't touch the chassis, bare pot shafts or anything while it's on... It's a live chassis set. The circuitry is connected to the wall plug with no transformer!
No need for a IF alignment?
Also you forgot to replace the Bumble-Bee capacitor that's front and bottom.
But Mr. AH, you didn't appear to check any of the tubes.